BACKGROUND: Positive vascular remodeling after percutaneous coronary intervention (PCI) using drug-eluting stents may be associated to a high dose of an anti-proliferative agent and/or local toxicity of the synthetic polymer. This may lead to late incomplete aposition of the struts, acting as a late/very late thrombosis risk factor. Our objective was to assess the vascular response secondary to sirolimus drug-eluting stent implantation using different doses and patterns of elution by means of serial intravascular ultrasound (IVUS) analysis. METHOD: We assessed 50 patients with low to moderate cardiovascular risk divided into 3 groups according to the sirolimus dose and pattern of elution: group 1, Cypher® (7.7 µg sirolimus/mm, durable polymer sirolimus-eluting stent); group 2, Cypher Redox® (3.1 µg sirolimus/mm, durable polymer sirolimus-eluting stent); and group 3, VESTAsyncTM (2.9 µg sirolimus/mm, polymer-free sirolimus-eluting stent). RESULTS: In the 10 ± 1 month followup, Cypher®, Redox® and VESTAsyncTM stents showed a late luminal loss of 0.16 ± 0.36 mm, 0.24 ± 0.33 mm, 0.37 ± 0.24 mm, respectively (P = 0.19). Serial IVUS analysis showed Cypher® and Redox® stents with mild positive vascular remodeling translated by non-significant vessel volume increase of 0.1 ± 1.6 mm³/mm and 0.5 ± 0.6 mm³/mm, respectively. On the other hand, there was no positive vascular remodeling in the VESTAsyncTM group (-0.3 ± 1.9 mm³/mm). CONCLUSIONS: There was no linear relationship between increasing sirolimus doses and positive vascular remodeling, suggesting this vascular event may be related to the presence of a synthetic polymer.
Drug-eluting stents; Sirolimus; Ultrasonography, interventional
